Connector systems are commonly formed with a metal housing that contains an insulator that retains contacts. A weight reduction may be achieved for avionics applications, by constructing the housing of plastic, with a metal plating to guard against electromagnetic interference. However, inasmuch as a metal plating usually has a maximum thickness less than 0.002 inch, the metal cannot withstand severe electromagnetic pulses such as are produced by lightning or nuclear devices, in aircraft whose skins are constructed of composite materials rather than metal.
Another approach to reducing the weight of electrical connectors is to use a hybrid construction, where the connector housing includes a plastic shell that surrounds a metal insert, where the metal insert is of a thickness (generally at least 0.02 inch) at least an order of magnitude greater than that of a thick plating. However, this can give rise to difficulties in assuring that the hidden metal inserts of a mating plug and receptacle make good electrical contact with each other. Also, steps must be taken to protect the metal insert or other internal metal parts against corrosion, especially in the wide area where the outside of the metal insert lies against the inside of the plastic shell. A hybrid connector housing construction which assured good contact between the metal inserts of mating connectors, while protecting the metal inserts against corrosion, would be of considerable value.